planner: preprocessor add CTE recursive check when handleTableName (#34133)

bindinfo/handle.go

@@ -961,8 +961,7 @@ func GenerateBindSQL(ctx context.Context, stmtNode ast.StmtNode, planHint string
 			withIdx := strings.Index(bindSQL, "WITH")
 			restoreCtx := format.NewRestoreCtx(format.RestoreStringSingleQuotes|format.RestoreSpacesAroundBinaryOperation|format.RestoreStringWithoutCharset|format.RestoreNameBackQuotes, &withSb)
 			restoreCtx.DefaultDB = defaultDB
-			err := n.With.Restore(restoreCtx)
-			if err != nil {
+			if err := n.With.Restore(restoreCtx); err != nil {
 				logutil.BgLogger().Debug("[sql-bind] restore SQL failed", zap.Error(err))
 				return ""
 			}

cmd/explaintest/r/cte.result

@@ -730,3 +730,78 @@ c1	c2
 2	1
 2	2
 2	3
+use test;
+drop table if exists t1, t2;
+drop view if exists v1;
+create table t1 (a int);
+insert into t1 values (0), (1), (2), (3), (4);
+create table t2 (a int);
+insert into t2 values (1), (2), (3), (4), (5);
+drop view if exists v1,v2;
+create view v1 as with t1 as (select a from t2 where t2.a=3 union select t2.a+1 from t1,t2 where t1.a=t2.a) select * from t1 order by a desc;
+create view v2 as with recursive t1 as ( select a from t2 where t2.a=3 union select t2.a+1 from t1,t2 where t1.a=t2.a) select * from t1 order by a desc;
+create database if not exists test1;
+use test1;
+select * from test.v1;
+a
+5
+4
+3
+2
+select * from test.v2;
+a
+6
+5
+4
+3
+use test;
+drop table if exists t ,t1, t2;
+create table t(a int);
+insert into t values (0);
+create table t1 (b int);
+insert into t1 values (0);
+create table t2 (c int);
+insert into t2 values (0);
+drop view if exists v1;
+create view v1 as with t1 as (with t11 as (select * from t) select * from t1, t2) select * from t1;
+use test1;
+select * from test.v1;
+b	c
+0	0
+use test;
+drop table if exists t11111;
+create table t11111 (d int);
+insert into t11111 values (123), (223), (323);
+drop view if exists v1;
+create view v1 as WITH t123 AS (WITH t11111 AS ( SELECT * FROM t1 ) SELECT ( WITH t2 AS ( SELECT ( WITH t23 AS ( SELECT * FROM t11111 ) SELECT * FROM t23 LIMIT 1 ) FROM t11111 ) SELECT *  FROM t2  LIMIT 1  )  FROM t11111, t2 ) SELECT * FROM t11111;
+use test1;
+select * from test.v1;
+d
+123
+223
+323
+use test;
+drop table if exists t1;
+create table t1 (a int);
+insert into t1 values (1);
+drop view if exists v1;
+create view v1 as SELECT (WITH qn AS (SELECT 10*a as a FROM t1),qn2 AS (SELECT 3*a AS b FROM qn) SELECT * from qn2 LIMIT 1) FROM t1;
+use test1;
+select * from test.v1;
+name_exp_1
+30
+use test;
+drop table if exists t1,t2;
+create table t1 (a int);
+insert into t1 values (0), (1);
+create table t2 (b int);
+insert into t2 values  (4), (5);
+drop view if exists v1;
+create view v1 as with t1 as (with t11 as (select * from t1) select * from t1, t2) select * from t1;
+use test1;
+select * from test.v1;
+a	b
+0	5
+0	4
+1	5
+1	4

cmd/explaintest/t/cte.test

@@ -256,3 +256,61 @@ select * from t1 where c1 > all(with recursive cte1 as (select c1, c2 from t2 un
 
 explain select * from t1 where exists(with recursive cte1 as (select c1, c2 from t2 union all select c1+1 as c1, c2+1 as c2 from cte1 where cte1.c2=t1.c2) select c1 from cte1);
 select * from t1 where exists(with recursive cte1 as (select c1, c2 from t2 union all select c1+1 as c1, c2+1 as c2 from cte1 where cte1.c2=t1.c2) select c1 from cte1);
+# Some cases to Test Create View With CTE and checkout Database
+# With name is the same as the table name
+use test;
+drop table if exists t1, t2;
+drop view if exists v1;
+create table t1 (a int);
+insert into t1 values (0), (1), (2), (3), (4);
+create table t2 (a int);
+insert into t2 values (1), (2), (3), (4), (5);
+drop view if exists v1,v2;
+create view v1 as with t1 as (select a from t2 where t2.a=3 union select t2.a+1 from t1,t2 where t1.a=t2.a) select * from t1 order by a desc;
+create view v2 as with recursive t1 as ( select a from t2 where t2.a=3 union select t2.a+1 from t1,t2 where t1.a=t2.a) select * from t1 order by a desc;
+create database if not exists test1;
+use test1;
+select * from test.v1;
+select * from test.v2;
+# case
+use test;
+drop table if exists t ,t1, t2;
+create table t(a int);
+insert into t values (0);
+create table t1 (b int);
+insert into t1 values (0);
+create table t2 (c int);
+insert into t2 values (0);
+drop view if exists v1;
+create view v1 as with t1 as (with t11 as (select * from t) select * from t1, t2) select * from t1;
+use test1;
+select * from test.v1;
+# case
+use test;
+drop table if exists t11111;
+create table t11111 (d int);
+insert into t11111 values (123), (223), (323);
+drop view if exists v1;
+create view v1 as WITH t123 AS (WITH t11111 AS ( SELECT * FROM t1 ) SELECT ( WITH t2 AS ( SELECT ( WITH t23 AS ( SELECT * FROM t11111 ) SELECT * FROM t23 LIMIT 1 ) FROM t11111 ) SELECT *  FROM t2  LIMIT 1  )  FROM t11111, t2 ) SELECT * FROM t11111;
+use test1;
+select * from test.v1;
+# case
+use test;
+drop table if exists t1;
+create table t1 (a int);
+insert into t1 values (1);
+drop view if exists v1;
+create view v1 as SELECT (WITH qn AS (SELECT 10*a as a FROM t1),qn2 AS (SELECT 3*a AS b FROM qn) SELECT * from qn2 LIMIT 1) FROM t1;
+use test1;
+select * from test.v1;
+# case
+use test;
+drop table if exists t1,t2;
+create table t1 (a int);
+insert into t1 values (0), (1);
+create table t2 (b int);
+insert into t2 values  (4), (5);
+drop view if exists v1;
+create view v1 as with t1 as (with t11 as (select * from t1) select * from t1, t2) select * from t1;
+use test1;
+select * from test.v1;

parser/ast/dml.go

@@ -1048,6 +1048,51 @@ type CommonTableExpression struct {
 	Name        model.CIStr
 	Query       *SubqueryExpr
 	ColNameList []model.CIStr
+	IsRecursive bool
+}
+
+// Restore implements Node interface
+func (c *CommonTableExpression) Restore(ctx *format.RestoreCtx) error {
+	ctx.WriteName(c.Name.String())
+	if c.IsRecursive {
+		// If the CTE is recursive, we should make it visible for the CTE's query.
+		// Otherwise, we should put it to stack after building the CTE's query.
+		ctx.RecordCTEName(c.Name.L)
+	}
+	if len(c.ColNameList) > 0 {
+		ctx.WritePlain(" (")
+		for j, name := range c.ColNameList {
+			if j != 0 {
+				ctx.WritePlain(", ")
+			}
+			ctx.WriteName(name.String())
+		}
+		ctx.WritePlain(")")
+	}
+	ctx.WriteKeyWord(" AS ")
+	err := c.Query.Restore(ctx)
+	if err != nil {
+		return err
+	}
+	if !c.IsRecursive {
+		ctx.RecordCTEName(c.Name.L)
+	}
+	return nil
+}
+
+// Accept implements Node interface
+func (c *CommonTableExpression) Accept(v Visitor) (Node, bool) {
+	newNode, skipChildren := v.Enter(c)
+	if skipChildren {
+		return v.Leave(newNode)
+	}
+
+	node, ok := c.Query.Accept(v)
+	if !ok {
+		return c, false
+	}
+	c.Query = node.(*SubqueryExpr)
+	return v.Leave(c)
 }
 
 type WithClause struct {
@@ -1117,6 +1162,7 @@ func (n *WithClause) Restore(ctx *format.RestoreCtx) error {
 		if i != 0 {
 			ctx.WritePlain(", ")
 		}
+<<<<<<< HEAD
 		ctx.WriteName(cte.Name.String())
 		if n.IsRecursive {
 			// If the CTE is recursive, we should make it visible for the CTE's query.
@@ -1141,6 +1187,11 @@ func (n *WithClause) Restore(ctx *format.RestoreCtx) error {
 		if !n.IsRecursive {
 			ctx.CTENames = append(ctx.CTENames, cte.Name.L)
 		}
+=======
+		if err := cte.Restore(ctx); err != nil {
+			return err
+		}
+>>>>>>> fa5e19010... planner: `preprocessor` add CTE recursive check when `handleTableName` (#34133)
 	}
 	ctx.WritePlain(" ")
 	return nil
@@ -1153,11 +1204,9 @@ func (n *WithClause) Accept(v Visitor) (Node, bool) {
 	}
 
 	for _, cte := range n.CTEs {
-		node, ok := cte.Query.Accept(v)
-		if !ok {
+		if _, ok := cte.Accept(v); !ok {
 			return n, false
 		}
-		cte.Query = node.(*SubqueryExpr)
 	}
 	return v.Leave(n)
 }
@@ -1181,6 +1230,7 @@ func (n *SelectStmt) Restore(ctx *format.RestoreCtx) error {
 		}()
 	}
 	if !n.WithBeforeBraces && n.With != nil {
+		defer ctx.RestoreCTEFunc()()
 		err := n.With.Restore(ctx)
 		if err != nil {
 			return err

parser/parser.go

@@ -16698,6 +16698,9 @@ yynewstate:
 		{
 			ws := yyS[yypt-0].item.(*ast.WithClause)
 			ws.IsRecursive = true
+			for _, cte := range ws.CTEs {
+				cte.IsRecursive = true
+			}
 			parser.yyVAL.item = ws
 		}
 	case 1497:

parser/parser.y

@@ -8363,6 +8363,9 @@ WithClause:
 	{
 		ws := $3.(*ast.WithClause)
 		ws.IsRecursive = true
+		for _, cte := range ws.CTEs {
+			cte.IsRecursive = true
+		}
 		$$ = ws
 	}
 

planner/core/preprocess.go

@@ -116,7 +116,7 @@ func Preprocess(ctx sessionctx.Context, node ast.Node, preprocessOpt ...Preproce
 	v := preprocessor{
 		ctx:                ctx,
 		tableAliasInJoin:   make([]map[string]interface{}, 0),
-		withName:           make(map[string]interface{}),
+		preprocessWith:     &preprocessWith{cteCanUsed: make([]string, 0), cteBeforeOffset: make([]int, 0)},
 		staleReadProcessor: staleread.NewStaleReadProcessor(ctx),
 	}
 	for _, optFn := range preprocessOpt {
@@ -176,6 +176,12 @@ type PreprocessExecuteISUpdate struct {
 	Node                    ast.Node
 }
 
+// preprocessWith is used to record info from WITH statements like CTE name.
+type preprocessWith struct {
+	cteCanUsed      []string
+	cteBeforeOffset []int
+}
+
 // preprocessor is an ast.Visitor that preprocess
 // ast Nodes parsed from parser.
 type preprocessor struct {
@@ -187,7 +193,7 @@ type preprocessor struct {
 	// tableAliasInJoin is a stack that keeps the table alias names for joins.
 	// len(tableAliasInJoin) may bigger than 1 because the left/right child of join may be subquery that contains `JOIN`
 	tableAliasInJoin []map[string]interface{}
-	withName         map[string]interface{}
+	preprocessWith   *preprocessWith
 
 	staleReadProcessor staleread.Processor
 
@@ -317,9 +323,12 @@ func (p *preprocessor) Enter(in ast.Node) (out ast.Node, skipChildren bool) {
 		}
 	case *ast.GroupByClause:
 		p.checkGroupBy(node)
-	case *ast.WithClause:
-		for _, cte := range node.CTEs {
-			p.withName[cte.Name.L] = struct{}{}
+	case *ast.CommonTableExpression, *ast.SubqueryExpr:
+		with := p.preprocessWith
+		beforeOffset := len(with.cteCanUsed)
+		with.cteBeforeOffset = append(with.cteBeforeOffset, beforeOffset)
+		if cteNode, exist := node.(*ast.CommonTableExpression); exist && cteNode.IsRecursive {
+			with.cteCanUsed = append(with.cteCanUsed, cteNode.Name.L)
 		}
 	case *ast.BeginStmt:
 		// If the begin statement was like following:
@@ -564,6 +573,19 @@ func (p *preprocessor) Leave(in ast.Node) (out ast.Node, ok bool) {
 		if x.Kind == ast.BRIEKindRestore {
 			p.flag &= ^inCreateOrDropTable
 		}
+	case *ast.CommonTableExpression, *ast.SubqueryExpr:
+		with := p.preprocessWith
+		lenWithCteBeforeOffset := len(with.cteBeforeOffset)
+		if lenWithCteBeforeOffset < 1 {
+			p.err = ErrInternal.GenWithStack("len(cteBeforeOffset) is less than one.Maybe it was deleted in somewhere.Should match in Enter and Leave")
+			break
+		}
+		beforeOffset := with.cteBeforeOffset[lenWithCteBeforeOffset-1]
+		with.cteBeforeOffset = with.cteBeforeOffset[:lenWithCteBeforeOffset-1]
+		with.cteCanUsed = with.cteCanUsed[:beforeOffset]
+		if cteNode, exist := x.(*ast.CommonTableExpression); exist {
+			with.cteCanUsed = append(with.cteCanUsed, cteNode.Name.L)
+		}
 	}
 
 	return in, p.err == nil
@@ -1422,15 +1444,19 @@ func (p *preprocessor) stmtType() string {
 
 func (p *preprocessor) handleTableName(tn *ast.TableName) {
 	if tn.Schema.L == "" {
-		if _, ok := p.withName[tn.Name.L]; ok {
-			return
+
+		for _, cte := range p.preprocessWith.cteCanUsed {
+			if cte == tn.Name.L {
+				return
+			}
 		}
 
 		currentDB := p.ctx.GetSessionVars().CurrentDB
 		if currentDB == "" {
 			p.err = errors.Trace(ErrNoDB)
 			return
 		}
+
 		tn.Schema = model.NewCIStr(currentDB)
 	}